题目

英语语法 虚拟语气：非真实条件句.should 是什么?
第一个should + have + done
You should have seen his face.(原句)这句是省略了从句,没错吧.
If the steamer should have left port at noon,it will be passing through the canal now.（原句）
不应该是:If the steamer had left port at noon,it would have been passing through the canal.
或者：If the steamer left port at noon,it will be passing through the canal now.
请指教上两句对吗?原句中的should have 那么最上头那句也不理解了.
第二个 should + be
If you should see Celia,give her my best wishes.(原句)
不应该是：If you saw Celia,give her my best wishes.
第三个 作表语
They suggested that we should meet at the station.(原句)请问有点像had better的感觉,没有时间的概念,也是非真实条件句吗?
suggest有这个短语呀 那么这样呢
It is desirable that everything should be ready by five o'clock.(原句)

提问时间：2020-11-11

答案

一：If the steamer should have left port at noon,it will be passing through the canal now.这句是混合虚拟~前面半句是对过去的虚拟~后面半句是对现在的虚拟~其中now就是现在的标志~
二：should表虚拟~
三：should也表虚拟~
四：desirable也是虚拟的标志语~It is desirable that 后面就要用虚拟~这类词还有很多necessary,essential之类~语法书上有的~把他们记住就行了~